Electrical Activation Studies of Silicon Implanted Al(x)Ga(1-x)N and Coimplanted GaN

A comprehensive study of the electrical activation of silicon implanted Al(x)Ga(1-x)N was performed as a function ion dose, anneal temperature, and aluminum mole fraction, Also, GaN coimplanted with silicon and nitrogen was investigated. Room temperature Hall effect measurements were used to determine carrier concentration and mobility. All the samples had a 500 angstrom encapsulant of AlN, and were implanted at room temperature with 200 keV silicon ions at doses ranging from 1x10(exp 13) to 1x10(exp 15) /sq cm. The GaN was also implanted with nitrogen under the same conditions in doses of 9x10(exp 12) to 9x10(exp 14) /sq cm, respectively. The samples were annealed at temperatures ranging from 1200 to 1350 degrees C for 30 to 120 seconds in a flowing nitrogen environment. The aluminum mole fractions considered were 0.2 and 0.3. The electrical activation efficiency for the Al(0.2)Ga(0.8)N annealed at 1350 degrees C and implanted with 1x10(exp 15) /sq cm was almost 90%. While the Al(0.3)Ga(0.7)N annealed at 1350 degrees C and implanted with 1x10(exp 15) / sq cm exhibited only about 42% activation. The activation efficiency for all the samples increased with anneal temperature, but decreased with aluminum mole fraction. The mobilities and the carrier concentrations demonstrate an increase with the anneal temperature. Although the Al(0.2)Ga(0.8)N exhibited almost perfect activation, the mobility was generally low, only 50 /sq cm/Vxs. The coimplanted GaN showed surprisingly poor results. The highest activation efficiency was only 37% for the sample annealed at 1300 degrees C and implanted with a dose of 1x10(exp 15) silicon ions /sq cm. The mobilities for these samples were high, on average 100 /sq cm/Vxs. The carrier concentration and activation efficiency were found to increase with implanted dose, The mobilities, however, decreased as the anneal temperature increased.Air Force Inst of Tech Wright-Patterson AFB OH School of Engineering and Management/dept of Engineering Physics is the author of 'Electrical Activation Studies of Silicon Implanted Al(x)Ga(1-x)N and Coimplanted GaN', published 2003 under ISBN 9781423513025 and ISBN 1423513029.